Machine including a plurality of crimping stations for preparing electrical harnesses

ABSTRACT

The present invention relates to a machine for preparing or making electrical harnesses. The machine includes a plurality of crimping stations situated along a horizontal linear conveyor (5) that moves clamps (6) holding lengths of wire (28). Each crimping device includes a tool (1) that is fed with terminals (50) from a reel (3). The tool (1) includes a fixed matrix (9, 10) and a moving punch (12, 13). The machine includes a press (4) that is movable in translation relative to the crimping tool in a direction parallel to the conveyor. The crimping tool includes means for holding the punch in a high position and the machine includes a servo-controlled actuator for driving the moving press. The technical field of the invention is that of manufacturing electrical harnesses.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a machine for preparing or fabricatingelectrical harnesses for fitting to motor vehicles or domesticappliances, for example.

The technical field of the invention is that of manufacturing electricalharnesses.

2. Summary of the Prior Art

Various types of machine are already known for preparing or fabricatingelectrical harnesses, which machines include a plurality of modules forcrimping terminals on previously-stripped ends of lengths of wire.

U.S. Pat. No. 4,375,229 (Mikami et al.) describes a machine forpreparing lengths of electrically conductive wire and that is controlledby an automatic control device. That machine includes a plurality ofmodules disposed on a first side of a conveyor, with lengths of electricwire in the form of loops being displaced by the conveyor on a secondside thereof. The machine comprises, disposed in succession along theconveyor: an electric wire feed device; a wire cutting device to formlengths of electric wire; a device for looping back one end of eachlength so that the lengths form loops, with both ends of each lengthbeing held by clamps that are displaced by the conveyor; downstream fromthose first elements, the machine includes devices for stripping theends of the lengths of wire; a sensor for monitoring stripping; and thena plurality of devices or presses for crimping terminals onto the endsof the lengths of wire being displaced by the conveyor.

Similar machines are also known in which two parallel conveyors areprovided, each length of wire being held in the vicinity of each of itstwo ends by a clamp located on a respective one of the two conveyors,the central portion of the wire hanging freely (under its own weight) ina loop between the two conveyors, e.g. as described in European patentapplication EP 7 681 (Utilux).

The present invention consists in an improvement in machines of thosetypes for preparing lengths of wire for fabricating electricalharnesses.

The advantage of the machine described in the above-referenced Mikamipatent and resulting from the presence of a plurality of crimpingstations disposed along the conveyor is that it enables different typesof terminal to be crimped onto the lengths of wire being displaced bythe conveyor without it being necessary to stop the machine to replacecrimping tools (or a portion of a crimping tool sometimes known as a"applicator"), given that each tool is specifically adapted to adetermined type of terminal and needs replacing by other tools adaptedto terminals of other types.

The use of an automatic machine of that type is particularlyadvantageous when the machine is used on a continuous basis, and isgiven characteristics that enable it to manufacture different lengths ofwire, fitted with different terminals, for making up various types ofelectrical harness.

It can thus be necessary to multiply the number of crimping stationslocated along the conveyor, and that can give rise to machines forpreparing lengths of wire that are very bulky and very expensive.

The problem posed consists in obtaining machines for preparing lengthsof wire fitted with terminals for fabricating electrical harnesses, andenabling terminals of several different types to be crimped onto thelengths of wire, while limiting the size of such machines and also theircost.

SUMMARY OF THE INVENTION

The solution to the problem posed consists in providing a machine forpreparing (or fabricating) electrical harnesses and including aplurality of devices (or stations) for crimping terminals onto thestripped ends of lengths of electrically conductive wire, in which saidcrimping stations are situated along a horizontal linear conveyor thatmoves clamps holding the ends of lengths of wire; each of said crimpingdevices essentially includes a tool that is fed with terminals takenfrom a strip wound on a reel, which tool includes a fixed matrix and apunch that is movable, e.g. vertically; and said machine formanufacturing electrical harnesses includes a press that is movable intranslation parallel to said conveyor in such a manner as to take up aposition facing one of said crimping tools and then to actuate saidcrimping tool by displacing its punch. The crimping tool may include(indexing or return) means for holding the moving punch in a high (ordisengaged) position. The machine may further include an actuator fordriving said moving press in translation, which actuator isservo-controlled and enables the moving press to be brought intocoincidence with any one of said crimping stations. The moving press mayinclude a moving member (or slide) for transmitting force and that is ofa shape which is complementary to the shape of the moving punch (or thesupport for the moving punch) enabling the press to actuate the clampingtool when in coincidence therewith.

In a preferred embodiment the moving press is driven by a motor (whichmay be mechanical, electrical, hydraulic, or pneumatic) which iscontrolled by a central unit, via for example a lead screw rotatablyco-operating with a nut that is mechanically associated with said press;

said moving press is fitted with an actuator that is hydraulic and/orpneumatic;

said hydraulic or hydropneumatic actuator acts directly (via its rod) onsaid crimping tool, i.e. without interposing a device for transformingmovement from the actuator rod (such as a force multiplier device) or adevice for redirecting or modifying the direction of the force exertedby the actuator rod;

each of said fixed crimping tools includes a spring for returning saidpunch to its high (or disengaged) position;

said machine includes a plurality of crimping tools that are preferablysubstantially regularly spaced at a pitch of less than 200 millimeters,and includes means for displacing said moving press suitable for causingsaid press to move at a linear speed of not less than 0.3 meters persecond (m/s), e.g. of the order of 0.5 m/s to 1 m/s;

said moving press includes a sensor for measuring the crimping force,e.g. a piezoelectric sensor integrated in said moving press, e.g. in ayoke provided at the end of the actuator rod of said press;

a sensor for sensing the position of the moving member for applying theforce of the press (the rod of a hydraulic or hydropneumatic actuator)is integrated in said moving press in order to measure the displacementof the moving punch with which the moving press coincides in order todeduce the crimping stroke;

said moving press slides (or runs on wheels) on one or more railsparallel to the longitudinal axis XX of the conveyor, which rails aremounted on the framework of said machine via spacers that aresubstantially regularly spaced apart, e.g. at a pitch that is a multipleof the spacing of said crimping tools;

said machine includes at least two moving presses on at least two commonrails, and includes two independent drive systems for moving said movingpresses in translation, and includes two servo-controlled electricmotors for driving said moving presses;

said machine includes a controller (an electronic monitoring and controldevice) associated with each moving press, and preferably connected to acentral control unit for the various modules of said machine, saidcontroller controlling electrically controlled valves for sequentialfeed of hydraulic fluid to the actuator of said moving press; and

said crimping stations (or devices) are situated along (a first side of)a horizontal (rectilinear) linear conveyor, e.g. having a belt or achain, which conveyor moves pairs of adjacent clamps holding lengths ofwire in the form of loops, the clamps holding the lengths of wire in thevicinity of their two ends so as to move said ends of the lengths ofwire successively past said crimping devices; said clamps hold thepreviously stripped ends of the lengths of wire that are in the form ofloops so that the ends point towards the side of the conveyor where thecrimping stations are situated, and so that they extend perpendicularlyto the axis of the conveyor and preferably along an axis that issubstantially horizontal.

Because of the characteristic of the invention whereby the machineincludes a moving press that moves so as to actuate one of thepermanently installed (fixed) crimping tools on the table or frameworkof the machine, as a function of commands applied to the displacementmeans and commands applied to the moving press itself via controllers(electronic monitoring and control devices, and optionally under thesupervision of a central control and monitoring unit for the variousmodules of the machine), it is possible to obtain a machine that is ofsmall size because the size of the various crimping tools disposed alongthe conveyor is much smaller than the size of traditional crimpingpresses that include not only the tool but also the device for applyingforce on the tool, which device is generally rather bulky, whether thedevice is mechanical or pneumatic or otherwise.

It is thus possible to reduce the pitch (measured in a directionparallel to the longitudinal axis of the conveyor) from a value that isgenerally of the order of 300 millimeters or more to a pitch that is ofthe order of about 100 millimeters.

The cost of a machine of the invention is considerably reduced in that asingle crimping tool actuator device (or crimping press) is provided toactuate a plurality of tools, thereby achieving savings; the additionalmechanism for displacing the moving press and the corresponding cost isless than the cost of additional presses (conventionally provided at onepress per tool) once each moving press is used in association with atleast three tools; a moving press is preferably provided to actuate fiveto 20 tools located on the framework of the machine.

In a machine of the invention, it is advantageous to use moving pressesfitted with a hydraulic or pneumatic actuator in order to reduce theweight of the moving press and thus make it possible to increase itsdisplacement speed without requiring a press drive system that is itselftoo bulky; moving presses obtained using hydraulic or pneumaticactuators are lighter in weight than mechanical presses e.g. of the kinddescribed in U.S. Pat. No. 4,611,484 (MacKinssinger et al.).

It is also particularly advantageous to use a press fitted with anactuator whose rod directly actuates the crimping tool, as compared withcrimping presses fitted with actuators such as those described inBritish patent 1 376 877 (George William Rider) in which the pressincludes a device for transforming the movement of the actuator rod soas to multiply or modify the force exerted by the rod for exerting aforce on the punch, and also a device for modifying the direction inwhich the force is applied; it is thus particularly advantageous for themovement of the actuator to be at least parallel with if not directly inline with the direction of movement of the crimping punch.

The numerous advantages provided by the invention will be betterunderstood from the following description which refers to theaccompanying drawings showing, without any limiting character, variousembodiments of the machine of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic plan view showing the main components of amachine for preparing lengths of wire for making up electricalharnesses.

FIG. 2 is a section view on a plane perpendicular to the longitudinalaxis of the conveyor, showing a moving press fitted to a machine of theinvention for preparing lengths of wire.

FIG. 3 is a diagram of a hydropneumatic actuator for actuating a movingpress of the invention, together with control and monitoring devicestherefor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, the machine for preparing lengths of wire comprisesa linear or rectilinear conveyor 5 extending along a longitudinal axisXX that is preferably horizontal; the conveyor may be an endless belt ora chain, and it is fitted with clamps 6 for holding lengths of wire 28disposed in loops, each length of wire being held in the vicinity ofeach of its two ends; thus, two adjacent clamps 6 in successivepositions on the conveyor 5 hold the two ends of a length of wire 28that forms a loop, the two ends being situated on a first side of theconveyor 5 and the loop (i.e. the central portion of the length of wire)being situated on a second side of the conveyor.

On the first side of the conveyor, i.e. the side where the ends of thelength of wire are situated, the following are provided in successionand in conventional manner: a device 34 for preparing lengths of wirefrom an electrically conductive wire 35 that is paid out from a wirestorage reel 36.

Thereafter (with reference to the direction in which lengths of wire aredisplaced along the machine by the conveyor 5), the machine includes adevice 37 for stripping the ends of the lengths of wire.

In accordance with the invention, the machine then includes a pluralityof crimping tools 1 disposed along the conveyor 5 and always on the sameside thereof, i.e. on the side where the ends of the lengths of wire aresituated, which tools 1 are regularly spaced apart at a small pitch 39,e.g. of about 100 mm.

Each of the crimping tools 1 may be fed with crimping terminals by arespective reel 3 situated behind the machine (to the left in FIG. 1);said terminals are packaged so as to constitute a strip that is woundonto the reel 3, as can also be seen in FIG. 2.

When the length 40 of the reels 3 as measured in a direction parallel tothe longitudinal axis XX of the conveyor is greater than the pitch 39 atwhich the crimping tools are spaced apart, the reels may be disposed ina staggered configuration (as shown in FIG. 1), i.e. two successivereels have their respective axes (referenced 24 in FIG. 2) offsetvertically, so that the pitch 38 between two successive reels 3 is equalto the pitch 39 separating two tools 1, in spite of the fact that thewidth 40 is greater than said spacing pitch.

As shown in FIG. 1, the machine includes two rolling or sliding rails 17on which two moving presses 4 can roll or slide so as to move along therails, i.e. parallel to the longitudinal axis XX of the conveyor 5.

As shown particularly in FIG. 2, each moving press 5 may be fitted atits bottom end with a nut 22 suitable for co-operating with a lead screw19 extending parallel to said longitudinal axis XX of the conveyor; saidscrew 19 may be driven by an electric motor 21 servo-controlled by acontroller 33 to cause the moving press 4 to move in a directionparallel to said axis XX, thereby bringing it level with one of thecrimping tools 1 in order to perform the operation of crimping aterminal of a predetermined type onto an end of a length of wire.

The various terminal feed reels 3 shown in FIG. 1 preferably receiveterminals of different respective types.

As shown in FIG. 1, each moving press may be controlled by a controller33 connected by a cable 60 to the press in the event of the controllerbeing fixed and the press being moving; or else the controller may beintegrated in the moving press, as shown in FIG. 2.

The controllers 33 for monitoring and controlling each module of themachine may all be connected to a central control unit 59 as also shownin FIG. 1.

With reference to FIG. 2, it can be seen that in accordance with theinvention a base 8 receiving a wire end termination tool 1 is disposedon the framework 7 of the machine for preparing lengths of wire. Thewire end termination tool is for attaching terminals to leads, forexample electrical terminals to ends of the lengths of wire 28. In theembodiment described, the tool 1 is a crimping tool. The bottom portionof each crimping tool essentially includes anvils (or matrices) 9 and 10adapted respectively to the profile of the insulation and to the profileof the stripped portion of the end 29 of each length of wire 28 (wherethe lengths are themselves held in the vicinity of said ends by clamps 6displaced by the conveyor 5 along the longitudinal axis XX which isperpendicular to the plane of FIG. 2).

Terminals for crimping onto said ends of the lengths of wire arepackaged in the form of a strip 2 wound or rolled up on a reel 3 havingan axis of rotation 24 and held by a support 29 connected to theframework 7 of the machine.

The tool 1 also includes an essential portion constituted by punches 12and 13 respectively adapted to the matrices or anvils 9 or 10, whichpunches are carried by a punch carrier 11 that is vertically movable,i.e. along an axis ZZ; the tool 1 is permanently mounted on theframework 7 via the base 8 and in a machine of the invention it includesa return spring 15 urging it to a disengaged position, i.e. a highposition for the punches 12 and 13 so that when a punch is not actuatedby the moving crimping press, the ends 29 of the lengths of wire aredisengaged and those lengths of wire which are not to be crimped by thetool in question are free to move between the punch and the matrix.

The crimping tool 1 of a machine of the invention also includes a nose(or adapter) 14 disposed at the top of the tool, mechanically linked tothe punch and serving as an interface between the tool and the free endof the actuator rod of a hydropneumatic actuator 30 provided in themoving press 4.

The actuator rod situated at the bottom of the actuator and movablealong the vertical axis ZZ relative to the body of the actuator thusincludes a yoke 20 (or temporary link or adapter) of profilecomplementary to the profile of the nose 14 and thus suitable forengaging therein so that when the moving press 4 is disposed facing thetool 1 it is possible to transmit drive from the actuator rod 30 to thepunches 12 and 13 via said nose 14 and said punch carrier 11; engagementis ensured firstly by the complementary shapes of the yoke and the nose,and secondly by the moving punch being returned or indexed into thedisengaged position.

As shown in FIG. 2, the moving press 4 comprises a housing (or cover orbox) 31 mounted on a moving carriage 16 and containing saidhydropneumatic actuator 30 fitted with electrically controlled valves 32for feeding it with fluid, and as illustrated in the figure it may alsoinclude a controller 33 or sequencer apparatus for monitoring andcontrolling the operation of said press.

As shown in this figure, it can be seen that the carriage 16 that formsa part of the moving press 4 is fitted at its bottom end with shoes orbearings 23 suitable for sliding or rolling on rails 17A and 17B thatare securely and rigidly fixed to the framework 7 via spacers 18 thatserve to support said rails.

Said rails 17A and 17B extend along respective axes 25 and 26 parallelto the longitudinal axis XX of the conveyor 5.

A lead screw 19 is also provided, having its longitudinal axis 27parallel to said axes 25, 26, and XX, and suitable for co-operating witha nut 22 fixed beneath the bottom face of the carriage 16 so thatrotation of the lead screw 19 about its axis 27 causes said moving press4 to be driven along said axis 27, thereby enabling it to be positionedfacing a crimping tool 1 that it is to actuate.

With reference to FIG. 3, it can be seen that a moving press of theinvention includes an actuator of the hydraulic cylinder type 30enabling actuation of the tool punch to be controlled, which actuator isprovided with a power supply circuit delivering pneumatic energy from asource 47 provided by feed at constant pressure and at controlled flowrate for the hydraulic or hydropneumatic actuator.

A sequencer or controller 33 serves to control the feed of hydraulicfluid to the actuator 30 in such a manner as to generate a force on thetool (punch) against the terminal to be crimped, in application of adetermined working cycle (i.e. displacement along the axis ZZ).

By way of example, the hydropneumatic actuator 30 may be an actuatormanufactured by the German company PRESSO TECHNIK GmbH, and sold inFrance by DIMA FLUID of 92600 Asnis.

A crimping force sensor, e.g. of the piezoelectric type, may beintegrated in the yoke mounted at the end of the actuator rod of themoving press; this sensor is mounted substantially flush and comes intocontact with a face of the nose of the punch carrier of the crimpingtool when the moving press coincides with said tool, so that thecrimping force exerted by the press on the crimping tool as transmittedto said nose by said yoke is measured by the sensor.

The actuator 30 is fed by electrically controlled valves 32A and 32Bwhich are connected to a source of compressed air 47, and which enablethe compressed air to be delivered respectively to chambers 46 and 55 oneither side of a piston 54, or else to connect said chambers to exhaust,as a function of control signals issued by the controller 33 viaelectrical connections 57.

Operation is as follows:

the drive valves 32A and 32B are actuated so that compressed airpenetrates into the chamber 46 while chamber 55 is connected to exhaust;and

the piston 54 then moves at high speed while developing a low forceuntil contact is made with the terminal to be crimped.

The reaction from the terminal to be crimped causes a sequencer valve 98to be triggered (i.e. opened); compressed air then passes from thechamber 46 to the chamber 41; the amplifier piston 42 then causes itsplunger 44 to penetrate through the high pressure seal 97 separating thehigh pressure chamber 61 from the oil compensator 45 and providingsealing up to a pressure of about 400 bars, for example; this highpressure of oil that obtains in the chamber 61 acts on the high pressureface of the piston 54 and urges it downwards over a stroke that may beas much as 24 mm, for example.

Crimping is thus performed, after which the control valves 32A and 32Bare actuated again and the sequencer valve 98 automatically connects toexhaust as does the chamber 41; the piston 54 and the amplifier piston42 then return to the starting position (high position).

It can also be seen in this figure that the rod 51 of the actuator islinked directly to the punch carrier 11 via a yoke 20 suitable forco-operating in an engageable nose 14 provided at the top of the toolcarrier 11 which receives the punches 12 and 13 for crimping a terminal50 on the end 29 of a previously stripped length of electric wire, afixed anvil 9, 10 also being provided in conventional manner.

The figure also shows a sensor 53 for monitoring the position of theactuator rod 51 and connected to the controller 33 for controllingoperation of the actuator 30 of the moving press.

I claim:
 1. A machine for preparing electrical harnesses, comprising aplurality of wire end termination stations situated along a horizontallinear conveyor that displaces clamps holding lengths of wire, each ofthe termination stations comprising a crimping tool fed with terminalsfrom a reel, said tool including a fixed matrix and a moving punch, saidmachine further comprising a press that is movable in translationrelative to the crimping tool in a direction parallel to said conveyor,said crimping tool having means for holding the moving punch in a highposition, said machine further comprising an actuator for moving saidpress in translation, said press including a moving member fortransmitting crimping force to the moving punch.
 2. The machineaccording to claim 1, wherein said press includes a sensor for measuringthe crimping force, the sensor being integrated in said press.
 3. Themachine according to claim 1, wherein a sensor is integrated in saidpress for sensing a position of the moving member for applying force. 4.The machine according to claim 1, wherein said press slides on at leastone rail parallel to said conveyors, said rail being mounted on aframework of said machine via spacers that are substantially regularlyspaced apart.
 5. The machine according to claim 4, comprising at leasttwo presses that are movable on at least two common rails, furthercomprising two independent drive systems for said presses and twoservo-controlled electric motors for driving said presses.
 6. Themachine according to claim 1, wherein the clamps hold two ends of eachlength of wire that is in a form of a loop, the two ends pointingtowards the side of the conveyor where the crimping stations aresituated, and being substantially horizontal and perpendicular to theaxis of the conveyor.
 7. The machine according to claim 1, wherein saidpress is fitted with a hydraulic actuator that acts directly on saidcrimping tool.
 8. The machine according to claim 1, wherein each saidcrimping tool comprises a spring returning said punch to a disengagedposition.
 9. The machine according to claim 1, comprising a plurality ofcrimping tools spaced apart at a pitch of less than 200 millimetres, andhaving an actuator for displacing said press at a linear speed of notless than 0.3 meters per second.
 10. The machine according to claim 1,including a controller associated with each press, and connected to acentral control unit for controlling the various modules of saidmachine, said controller controlling electrically controlled valves forfeeding the actuator of said press with fluid.